Create Nagios Icons

If you ever tried to make Nagios Status-Map a little nicer by adding some dependencies and some pretty icons, you have probably came across some little collections/packs of icons at NagiosExchange.
But if you need a special one, you must do it by yourself.
And you probably noticed that you need images with .gd2 extension
Here is how to convert a PNG image into .gd2 (GD Graphics Library format)